Sulze ('22), Edwards and Condorelli ( '28), Marshall and Grafflin ( '28), Marshall ( '30) and Smith ( '30) have presented data on the composition of the urine of marine teleosts. The results, in general, have indicated a high urinary chloridc and a low total nitrogen concentration associated with a relatively high urine flow. GrolIman ('29) has shown that the urine of Lophius, taken immediately from fish caught on the Grand Banks, is low in chloride and high in total nitrogen. Grafflin ('31) has shown that the high urinary chloride, low total nitrogen, and high urine flow of the sculpin and toadfish are results of experimental manipulation, and if precautions are taken with handling, low urine flows (less than 4 cc. per kilo per day) may be obtained with chloride contents of zero to trace and total nitrogens of 100 mg. per cent or above. The present investigation was undertaken to ascertain the composition of the urine of representative normal marine teleosts, and to find what changes in composition occur during the diuresis accompanying experimental manipulations. I n this investigation analyses were made for chloride, sulfate, phosphate, magnesium and creatine.
Results obtained on the common sculpin, Myoxocephalus octodecimspinosus ; the daddy sculpin, Myoxocephalus scorpius ; the silver hake, Merluccius bilinearis ; the hake, Urophycis tenuis ; the grey sole, Glyptocephalus cynoglossus ; thehaddock,Melanogrammus aeglifinis ; the rusty dab,Limanda ferruginea ; the goosefish, Lophius piscatorius, are presented ' I t is possible that some of the variability of phosphate and magnesium exeretion in these fish results from the ejection from the bladder of solid magnesium phosphate, excreted by the kidneys at some earlier time, but remaining in a precipitated state till a later collection period.